.nav{
    width: 100%;
    height: 1.707rem;
    position: fixed;
    background-color: #ffd161;
    top: 0;
    z-index: 99;
    overflow: hidden;
}

.nav .back-icon{
    float: left;
    width: 0.72rem;
    height: 0.72rem;
    background-image: url("back.png");
    background-size: cover;
    margin-top: 0.5rem;
    margin-left: 0.2rem;
}

.nav .title{
    font-size: 0.453rem;
    color: #000;
    line-height: 1.8rem;
    text-align: center;
}